Electric switch



(No Model.)

E. THOMSON.

ELECTRIC SWITCH. N0. 32163. Patented July 7,1885.

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l UNITED STATES PATENT Ormea...

ELIHU THOMSON, OF LYNN, MASSACHSETTS, ASSIGNOR TO THE THOMSON- HOUSTON ELECTRIC COMPANY, OF CONNECTICUT.

ELECTRIC s'wir'ol-i.

SPECIFICATION forming part of Letters Patent No. 321,463, dated July '7, 1385.

(N model.)

To @ZZ whom, it may concern:

Beit known that I, ELIHU THOMSON, a citizen of the United States, and a resident of Lynn, in the county of Essex and State of Massachusetts, have invented certain new and useful Improvements in Electric Switches, of which the following is a specification.

My invention relates to switching devices to be employed with incandescent electric Io lamps or other electric apparatus operated or controlled by electric current, and is intended more especially for use upon circuits supplied with rapidly-alternating or reversed currents.

The object of theinvention is more especially I5 to provide a simple and effective means for extinguishing` incandescent electric lamps, or for varying their powers; but my invention may be used in connection with any electric apparatus for varying the flow of current 2O through it or for entirely cutting off the iiow.

In carrying out my invention I make use of what I term a reactive coil,7 by which I mean a coil having high self-inductive or counter-electromotive capacity, or one whose power or capacity to oppose the flow of alternating electric currents through it shall be due not so much to the electric resistance of its wire coils as to the well-known extra or counter-induced currents set up in its coils, and which 3o currents, as well known in the art, tend to oppose the exciting, interrupted, or alternating currents. A well-known form of such coil consists of a helix of insulated wire wound over a core of iron, consisting of a bundle of iron wires or other mass of iron, subdivided or not. The core of such coil I make adjustable, and I combine it with the lamp or other device and with suitable switching appliances, so that in one position of the core-that is,

4o when the saine is within its coils-the lamp or other device will be shunted, cut out, or disconnected, while in the other extreme position-*that is, when the core is fully withdrawn-the coil will be shunted, cut out, or

disconnected. In intermediate positions the coils are in circuit with the lamp and oppose the passage of current to the lamp with an effect varying according to the position of the core.

5o One of the forms that my invention may take in practice is shown in the accoinpanying drawings, in which- Figure lis a diagram of circuits and apparatus illustrating the application of the in vention to an incandescent electric lamp. Figs. 2 and 3 illustrate, respectively, the position of the parts when the lamp is cut out and when it is burning with its greater power. Fig. et illustrates a modification of the switching appliances.

L indicates an incandescent electric lamp or other apparatus worked or operated by electric currents, and connected with a main, A B, leading from any source of alternating or reversed electric currents, (indicated at G.) Such source maybe the secondary of an induction-coil or an alternating-current dynamo of any desired construction.

R indicates a reactivecoil with a movable core, which core, when fully within the coils, 7o closes an electric switch, "V, of any desired construction, having proper connections, as indicated, for shunting or cutting out thelamp, and when fully out of the coils closes a switch, WV, of any desired construction, having proper 7 5 connections for shunting or cutting out the coils R. Suitable retractors open the switches when they are free from the influence of the movable core. The coil It is in a circuit with the lamp L, or should be so arranged that it 8o may be connected with the circuit thereof.

In the intermediate position of the core, as placed in Fig. l, both switches are open and the coil It and lamp L are in series. Figs. 2 and '3 show the positions of closure of the 85 switches V and XV, respectively.

The action is as follows: To extinguish the lamp the position, Fig. 2, is given when the reactive effect of coil It and core prevents undue iiow of current through It, although It is 9o of quite low resistance. The current is used in developing counter-electroinctive force and not heat, as in case of resistances being used to replace it. The full light of the lamp is obtained when the parts are in the position 9 5 shown in Fig. 3. where the coil R is shunted and the whole el'fect of the current is expended in L. In any intermediate position, as Fig; I,

the work is expended on the lamp L, and is the whole effect less the reactive effect of R, roo

which latter is more or less according to whether its core is in or out of the coil. The eect of R is to check the passage of current to the lamp 5 hence any desired lightingpower may be obtained in L, according to the position given to the core of R. The rapid alternation of current and the weight of the core conduce to cause said core to retain any position in which it may be placed. In Fig. et the two switches are combined into a single switch, movable by the core It upon the extremes of its movement. The action is in all respects the same as before.

I do not limit myself to any particular way of adjusting the reactive effect of the coil. The adjustments in the mass forni a division of the iron within the coil that may be adopted for this purpose of producing variations of reactive effects, and the principles upon which such adjustments operate, being well known in the art, need not be herein described. Any kind of adjustment will serve the purpose of my invention.

In my prior application, No. 88,741, I have described and claimed a reactive coil placed on an alternating-current circuit and properly constructed and combined with devices whereby it may act as a substitute for the resistance ofa lamp or other device when the latter is thrown out of action. I make no claim,

broadly, in this case to such invention, my present invention relating` simply to a combination into which such reactive coil enters as an element in a special way.

Vhat I claim as my invention isl. The combination, with an incandescent electric lamp or other electric apparatus, of a reactive coil having an adjustable core, and switch devices operated therewith for switching the current from the coil and the lamp, respectively, in extreme conditions of adjustment of the core.

2. The combination, with an incandescent lamp fed by alternating currents, of a reactive coil, a movable core for the latter, and switch appliances -for shunting current from the coils and lamp, respectively, said switch appliances being operatively related to the core so that in one position of the latter the lamp will be shunted and in the other position the coils will be shunted.

3. The combination, with an incandescent lamp fed by an alternating current, of a reactive coil having means whereby its reactive effects may be adj usted, and switch appliances operatively related to the adjusting devices so as to cut off the fiow of current to the lamp when the coil is adjusted to give the maximum reactive effects.

et. rlhe combination, with an electric lamp or other device fed with alternating currents, of a reactive coil and core therefor, means for adjusting the reactive effect, and switching appliances operatively related to the adjusting mechanism for switching the current from the lamp and the coils, respectively, in opposite extremes of adjustment.

Signed at Lynn, iu the county of Essex and State of ifassachusetts, this 17th day of May, A. D. 1884.

ELIHU THOMSON. iVitnesses:

W'. O. Wliiiinrrntn, E. B. DonN. 

